Spillway liner and method

ABSTRACT

A liner is formed in an excavated spillway by providing a plurality of rectangular flexible liner sections with each liner section having a parallel series of elongated continuous and adjacent tubular pockets pre-filled with a dry cementitious material or a fine granular material. The liner sections are provided with a surrounding generally flat perimeter boarder. The liner sections are laid into the spillway with their boarders overlapping and the boarders are secured together with the tubular pockets aligned in the same direction to form a continuous liner blanketing the spillway. The tubular pockets are arranged in the spillway with their elongated sides presented to the expected direction of water flow in the spillway. The liner sections may be anchored to the spillway with anchor pins.

CROSS REFERENCE

The present application is based upon U.S. Provisional Application No.61/399,103, filed on Jul. 7, 2010, for SPILLWAY LINER, the contents ofwhich are incorporated herein in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to erosion control and morespecifically to a method of lining spillways and ditches.

BACKGROUND OF THE INVENTION

Two current methods of lining spillways are placing stone in thespillway trench or pouring a concrete trench liner. Placing stone in thespillway can take days and requires several different pieces ofequipment, which allows a window of time for erosion of the spillwayduring placement of the stone. Pouring cement from the mixing truckrequires not only transporting cement, but also a considerable amount ofwater in the mix. If the cement must be pumped, then both a mixing and apumping truck are required.

As increasing emphasis is exerted on erosion control and the cost of thecurrent methods of placing stone in the spillway or lining the spillwaywith poured concrete are expensive. It is accordingly an object of thepresent invention to provide a method for forming a spillway liner whichcan be deployed quickly and at a reduced cost compared to the presentmethods of placing stone in the spillway or pumping concrete.

SUMMARY OF THE INVENTION

The spillway liner of the present invention is formed by providing aplurality of rectangular (4 sided, including square) flexible linersections, each having a parallel series of elongated continuous andadjacent tubular pockets containing a dry cementitious material or afine granular material, and having a surrounding generally flatperimeter boarder. A plurality of the liner sections are laid in thespillway with their boarders overlapping. The overlapping boarders aresecured together with the tubular pockets aligned in the same directionto form a continuous liner blanketing the spillway. The tubular pocketsare arranged in the spillway with their elongated sides presented to theexpected direction of water flow in the spillway. Presenting the filledpockets generally perpendicular to the fluid flow creates an energydissipating effect.

When the tubular pockets are pre-filled with a dry cementitiousmaterial, such as a rapid setting cement, the upper sheet surface of theliner sections are constructed of a water permeable material so thatafter the liner sections have been laid, they are saturated with waterin order to cure the cementitious material. The bottom sheet of theliner sections in this instance are made of a sheet material which isnon-permeable to water.

The overlapping boarders are provided with aligned grommets for securingthe liner sections to the spillway with anchor pins. The overlappingboarders of the liner sections may also be secured together with hookand loop fasteners.

The pre-filled liner system of the present invention can be deployedquickly and at a reduced cost compared to the present methods of placingstone in the spillway or pumping concrete.

The spillway liner sections are pre-filled with rapid setting cement orfine ground aggregate before transporting them to the work site.Pre-filling of the liner sections in an assembly line generates costsavings and less waste of the filling material. The liner sections maybe filled by different methods. One method is to hang the liner sectionsand allow the dry filler material to be gravity fed into the individualpockets of the section to be filled from a silo or from a screw feed.Alternatively, cement can be blown into the pockets while the linersection is in a horizontal or vertical position. The filled linersections can vary in length and width to accommodate different siterequirements, and the liner sections can be delivered to the work siteon reels or lying flat on pallets.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages appear hereinafter in the followingdescription and claims. The accompanying drawings show, for the purposeof exemplification, without limiting the scope of the invention orappended claims, certain practical embodiments of the present inventionwherein:

FIG. 1 is a schematic plan view of a single liner section forincorporation into the spillway liner of the present invention;

FIG. 2A is a schematic end view of the liner section of FIG. 1 with thepockets unfilled as seen along section line A-A;

FIG'S. 2B and 2C are schematic end views of the spillway liner sectionas shown along section line A-A of FIG. 1 with the pockets filled butprior to closure of the end to close the pockets in FIG. 2B and afterclosure of the end in FIG. 2C;

FIG. 3 is a schematic plan view of two spillway liner sections havingoverlapping boarders secured together illustrating the combining ofliner sections to form the spillway liner of the present invention;

FIG. 4 is an end view of a liner section for the spillway liner of thepresent invention illustrating an embodiment wherein the top layer sheetis water permeable and the water layer sheet comprising the linersection is water impermeable; and

FIG. 5 is a perspective view illustrating the spillway liner of thepresent invention as deployed in a spillway.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, the spillway liner 10 of the presentinvention (see FIGS. 3 and 5) is comprised of a plurality of rectangularflexible liner sections 11. Each liner section 11 is provided with aparallel series of elongated continuous and adjacent tubular pockets 12which contain a dry cementitious material or a fine granular materialdesignated as 13 in FIG. 2B. Each liner section 11 is surrounded by agenerally flat perimeter boarder 14.

The spillway liner 10 is constructed in the spillway 15, which isexcavated in the underlying earth 16 (see FIG. 5), by laying a pluralityof the liner sections 11 in the spillway 15 with their boardersoverlapping. The overlapping boarders 11 are preferably secured togetherby placing weights or rocks thereon or by hook and loop securementstrips (not shown). The tubular pockets 12 of each liner section 11 areall aligned in the same direction to form a continuous liner 10blanketing the spillway 15 as shown in FIG. 5. The tubular pockets 12are arranged in the spillway 15 with their elongated sides 17 presentedto the expected direction of water flow as indicated by arrows 18 inFIG. 5 in the spillway 15. The liner sections 11 are deployed intospillway 15 from the bottom 20 to the top 21 allowing overlap of the topor upper liner section 11 over the lower liner section 11 in similarfashion to shingles being laid upon a roof to thereby prevent water fromgoing under the liner sections 11.

The overlying boarders 14 have aligned grommets 22 for securing theliner sections to the spillway 15 with T-head anchor pins 19 (FIG. 3).

Each liner section 11 is constructed of an upper flexible sheet 24 and abottom flexible sheet 25 forming pockets 12 therebetween. See inparticular FIG. 2B. The series of elongated pockets 12 are either formedby providing flexible partitions 26 therebetween or by simply directlystitching upper sheet 24 to lower sheet 25 as illustrating in FIG. 2C.

The elongated pockets 12 are fillable from end 30 of liner sections 11.Upper sheets 24 and lower sheets 25 are separable at end 30 to provideaccess to the interior of the individual pockets 12 for filling. Afterfilling of the pockets 12 with a cementitious or fine granular material,the pockets 12 are closed off by closing the open end 30 which is sealedtogether with hook and loop securement strips or sewn together at theedge 32.

The spillway liner sections 11 are preferably pre-filled with rapidsetting cement or fine ground aggregate 13 before deploying the sectionsto the work site. Liner sections 11 may be filled by any number ofdifferent methods. One suggested method is to hang the liner section 11with one end 30 or 31 positioned at the top and allow the dry cement tobe gravity fed into the individual pockets 12 for filling from a silo ora screw feed. Alternatively, the dry cement can be blown into thepockets while the liner section is in a horizontal or verticalorientation.

With particular reference to FIGS. 2B and 2C, the upper sheet 24 at thebottom sheet 25, are usually constructed of a water permeable fabricwhen the filler material 13 is selected as a fine aggregate.

FIG. 4 illustrates a liner section 11 of the present invention with thepockets 12 formed into a slightly different shape or configuration. Inthis embodiment, the pockets 12 are filled with a dry fast settingcement and the pocket shapes are given a slightly differentconfiguration from that illustrated in the other figures to illustrate apossible variation. In addition, since the pockets 12 are filled with adry fast setting cement, the upper sheet 24 is a UV resistant waterpermeable fabric and the lower sheet 24 is a plastic sheet or a plasticimpregnated fabric which is non-permeable to water. Accordingly, oncethe liner sections 11 are deployed, water is sprayed on the top sheets24 of the liner sections blanketing the spillway 15 in order to allowthe cement to begin curing. Alternatively the liner section may besubmerged in fluid just prior to being laid. The result is that within afew hours of spraying water on the laid spillway liner 10, the spillwayis capable of handling water flow. Also, the thickness of the linersections 11 may be varied in order to change the resistance of thecompleted spillway liner 10 to water flow and to also accommodategreater flow in the spillway.

1. A method of forming a spillway liner comprising: providing aplurality of rectangular flexible liner sections, each having a parallelseries of elongated continuous and adjacent tubular pockets containing adry cementitious material or a fine granular material and having asurrounding generally flat perimeter border; laying a plurality of saidliner sections in a spillway with said borders thereof overlapping andsecuring said borders together with said tubular pockets aligned in thesame direction to form a continuous liner blanketing at least a portionof said spillway; said tubular pockets arranged in the spillway withtheir elongated sides presented to the expected direction of water flowin said spillway.
 2. The method of claim 1, said liner sections providedwith an upper sheet surface which is water permeable, and filling saidtubular pockets with dry cementitious material and saturating said linersections with water after being laid to cure said cementitious material.3. The method of claim 1, securing said liner sections to the spillwaywith anchor pins.
 4. A spillway liner for erosion control in spillwaysand ditches, comprising: a plurality of rectangular flexible linersections, each having a parallel series of elongated continuous andadjacent tubular pockets and a surrounding generally flat perimeterborder; said pockets having closable access fill openings along one edgeof each liner section; said pockets filled with dry cementitiousmaterial or fine granular material; said liner sections arranged in aspillway with adjacent of said borders overlapping and secured togetherwith said tubular pockets aligned in the same direction to form acontinuous liner blanketing at least a portion of said spillway with theelongated sides of said filled pockets presented to the expecteddirection of water flow in said spillway.
 5. The spillway liner of claim4, said liner sections having an upper water permeable sheet and saidpockets filled with cementitious material.
 6. The spillway liner ofclaim 5, said liner sections having a bottom sheet which isnon-permeable to water.
 7. The spillway liner of claim 4, saidoverlapping borders having aligned grommets for securing the linersections to said spillway with anchor pins.
 8. The spillway liner ofclaim 4, said overlapping borders secured together with hook and loopfasteners.